Pneumatic control valve



Jan. 2l, 1930. P. R. FORMAN PNEUMATIC CONTROL VALVE Filed Jan. 6. 1926 2 Sheets-Sheet 1 INVENTOR Y Each/7M 39mg? A ORNEYJ www \\\\\\%\W NN A Jan. 2l, T930. P. R. FORMAN 1,744,041

NEUMATIG CONTROL VALVE Filed Jan. 6. 192e 2 sheets-'sheet 2 35% (6 www Agua Jua;

Patented Jan. 21, 1930 UNITED NSTATES PATENT carica PARIS R. FORMAN, OF`RAI-IWAY, NEW JERSEY, ASSIGNOR TO NATIONAL PNEUMATIC COMPANY, OF NEW YORK, N. Y., A CORPORATION F WEST VIRGINIA PNEUMATIC CONTROL VALVE This invention relates to pressure control valves for operating door closing engines, and has for its object the production of a yielding valve to feed pressure into the exhaust end of the operating cylinder, whenever the exhaust pressure falls below a definite pressure, so as to always provide an air cushion on which the door operating cylinder closes; another object includes the provision of simple but effective means for utilizing the full force of the operating piston to insure a positive seal against leakage of'air to the exhaust; a still further object includes the provision of a double cupped yielding valve for supplying cushioning pressure in the exhaust end of the door operating cylinder under required conditions. p

Other objects will appear hereinafter, and I attain these objects by the construction illus- 2O trated in the accompanying drawing, in which Fig. 1 is a view in section of a door operating engine wherein the closing cylinder is provided with a yielding valve which embodies the principles of my invention.

Fig. 2 is a view in section similar to that of Fig. 1, with the yielding valve in pressure feeding position to build up sulicient pressure for the door closing piston to be cushf ioned, and

Fig. 3 is a similar sectional view with the yielding valve in sealed position and the door closing piston engaging said valve to hold the same secured. v

Fig. 4 is a bottom plan view of the movable '5 part of the control valve.

parte throughout the several views.

0 In the operation of pneumatic door contro1.

medium, as air, is supplied to the exhaust end of the operating cylinder in a door controlling engine (such as is shown in Fig. 1, for example), to thereby cushion the door closing piston 11 to thus prevent the door f from slamming and to positively lock the same in closed position `(as in Fig. 3). In this instance, I provide the head of the cylinder 10 with a yielding valve and valve cylinders of different bores. The yielding valve consists of a small cup 12 and a larger cup 13, whichare united end to end by a strong spring 14. The smaller cup carries a seal that is arranged to be firmly seated against gasket 15 in the cylinder head and plate 16, and this cup moves a short distance in the smaller cylinder 17. The large cup is arranged to engage the annulus 18 which forms a stop therefor, and this cup moves in a larger cylinder 19 in unison with the smaller cup to admit or cut off pressure which is supplied through the constant pressure feed 20. The head 21 of the door control piston 11 passes through the stop 18 and engages the cup 13 of the larger piston. In Fig. 3 the piston is shown in the door closed position to firmly hold the yielding valve sealed.

The control valve shown in Figs. 4 and 5 is that represented generally by the reference numeral 25 in Figs. 1 and 2. The valve body 43 is of a unitary construction which is adapted to be secured to a seat formed on the engine cylinder. The body portion 43 is provided with a central slightly raised platform 44 through which open the ports 30, 47, 49, 50, 51 and 52. The port 30 is connected by a passage 4G to which the feed pipe for the fluid pressure supply is connected. Ports 47 and 52 are connected by the passages 32 and 23, respectively, which extend to the rear surface of the valve body in a position to be in alignment with the corresponding passages in the walls of the cylinder. The passages in the valve body have been given the same numbers as the passages in the engine walls in order that it may be apparent that they are, in fact, extensions of each other. Similarly the ports 49 and 51 are connected by the passages 48 and 22. The port 50 is connected by a passage 31 which extends to the soY atmosphere and comprises the exhaust port. The movable port of the valve shown imF ig. 5 colnprises a disc or plate 40 having on the surface which contacts With the platform 44 the groove 33 comprising arcuate and circular portions united by a straight portion. This groove does not pass all the Way through the valve part 40. In a similar manner an arcuate groove 42 is provided which does not pass all the Way through `the valve part 40. Extending from V'the groove 33 along radial lines are tivo passages 24 Which connect With the ports 41 Which come to the surface of the movable valve part 40. The relative position of these ports and passages With respect to the ports on the \va`lve body is clearly shown in Figs. 1 and 2.

It will beinoted thata free exhaust 22 opens into the control cylinder 10 at some distance `from the cylinder :end and that the exhaust 23 .opens into'the cylinder at the head. This arrangement provides for a tree exhaust during the first portion of the piston stroke and as soon vas the :free exhaust is closed by the moving piston, the exhaust is open only to the yrestricted passage 24 which comprises a passage of Zreduced cross-sectional area and pressure builds up so that the piston is properly cushioned during the linishing stroke while the yielding valve functions to properly accomplish these results. Assuming now that the 4control 25 is set to door closing position, as shown in Fig. 1, for example, fluid pressure will be .admitted through port 3() connected Sto the feed l-ine and travel through the valve and passage 3 2 into the left hand cylinder forcing the pistons to the right. If the pressure inthe door closing end of the cylinder falls below a certain amount, it being understood that consta-nt pressure is applied at the port 20, `under these conditions the pressure medium Will unseat the smaller cup andthus permit required pressure to pass by Way of port 26 into the cylinder which is open to exhaust through the exhaust port 23, groove 33 in the valve seat and exhaust pipe 31 and perhaps also through exhaust port 22. Pressure noW builds up in the cylinder suiiiciently to move the two cups into sealed position again, While the door closing piston 11 advances and cuts off the free exhaust 22, itt it is not already cut off when the yielding valve functions, leaving open, however, the restricted exhaust through passages 23 and 24, groove 33 and passage 31 with sutiicient air supplied in the manner stated above, to cushion the piston as it reaches the extreme or door closed position (of Fig. 3). At the end of the closing motion of the piston, head 21 strikes the hub of cup 13 and so compresses spring 14 to thus place still more pressure on the smaller cup which is sealed to securely hold vthe seal shut and thereby prevent air from leaking into the exhaust end When the door Iis closed. The door is held closed by the pressure in the left hand cylinder as long as the valve is held in its door closed position shown in Figs. 1 and 2.

By means of the spring (14) between the tWo piston-like cups, provision is made to al- `Ways positively seat the piston head against the larger cup thereby to secure the seal of the smaller cup Without tedious and delicate adjustments of the door connections between the engine and the door. By this provision a certain amount of leeivay is allowed in the motion of the piston and easier adjustment is made so that the door is alivays fully closed when the seal is completed.

It is found in practice that a door operating engine equipped with my new yielding valve, and connections, functions perfectly and provides tor the control of the door, so as to hold the same in any position, and when released, the door closing piston Will continue its motion Without slamming, so that the door is always cushioned perfectly.

By operating the yvalve 25 during the door closing operation to cut oli the exhaust vand trap the remaining air in the cylinder it is possible to stop the door and hold it in any desired position depending upon the time when this valve is operated. If yat the time the valve 25 is operated to said exhaust the pressure in the exhausting end of the cylinder acting on the large cup 13 is not su'lilcient to hold the smaller' cup 17 seated, then passage 20 will be opened and suflicient luid pressure admitted to build up a pressure in the exhausting end of the cylinder equal to the trapped pressure inthe operating end of the cylinder. Thus the door Aupon the operation of valve 25 at the proper time, may be stopped and held at any desired position.

While I have described a speciic-embodiment of my invention as applied to a speciic case, I do not thereby desire to be understood as thus limiting myseli:l unduly, as various modiiications falling Wholly Within the spirit and scope of my invention will present themselves to those versed in the art.

What I claim, therefore, as new and useful, of my ovvn invention, and desire to secure by Letters Patent is:

1. In a door control mechanism, a cylinder having free and restricted exhaust passages, a piston arranged to move Within said cylinder, means for admitting pressure into said cylinder during the exhaust period thereofto thereby always assure a cushioning pressure in the cylinder With the end of the piston stroke and means controlling said yexhaust passages whereby said means and said means for admitting pressure during exhaust cooperate to hold the piston in any desired position.

2. In a door control mechanism, a cylinder having free and restricted passages, a piston arranged to move Within said cylinder, and

a yielding valve having opposed cups of unequal size to automatically admit and cut olf pressure medium to the exhaust end of the cylinder, said yielding valve having its larger cup directly exposed to the pressure medium in the cylinder and its smaller cup exposed to pressure medium directly from the source.

3. In a door control mechanism, a cylinder, a piston disposed to move back and forth in said cylinder, a valve member comprising a pair of cups and a yielding spring between said cups, one of said cups carrying a prese sure seal for regulating the inflow of pressure medium into the cylinder when said cylinder is operated as the retarding cylinder, the other of said cups tending to maintain the first mentioned cup seated to form said pressure seal and acting under the influence of the pressure medium in the cylinder.

4c. In a door control mechanism, a cylinder, a pneumatically operated piston in said cylinder, a yielding valve associated with said cylinder for automatically regulating the supply of pressure medium directly from its source to the exhaust end of the cylinder during the closing movement to thereby provide l regulated pressure in said cylinder end.

5; In a door control mechanism, a cylinder, a pneumatically operated piston in said cylinder, a flexible control valve associated with said cylinder, said valve comprising a pair of opposed cups, said cups being arranged to control the admission of pressure medium to the retarding cylinder and means whereby when the pneumatically operated 'piston reaches the end of its travel any supply of pressure is cut oli' from the end.

6. In a door control mechanism, a cylinder having free and restricted passages, a piston arranged to move within said cylinder, a yielding valve having opposed cups of un equal size to automatically admit and cut od pressure medium to the exhaust end ofthe cylinder, and means whereby when the piston reaches the end of its travel, pressure supply is cut off from the end of said cylinder.

7. In a door control mechanism, a cylinder, a piston disposed to move back and forth in said cylinder,a valve member comprising a pair of cups and a yielding spring between said cups, one of said cups carrying a pressure seal for regulating the inflow of pressure medium into the cylinder when said cylinder is operated as the cylinder, the other of said cups tending to maintain the first mentioned cup seated to form said pressure seal by exposure to the pressure medium in the cylinder and means for cutting O the pressure supply when the piston has reached the end of its travel.

8. In a mechanism of the type described, the combination comprising a cylinder, a pneumatically operated piston in said cylinder, said cylinder having a plurality of passages therein, a valve for controlling the admission and exhaust of fluid pressure to said passages, a flexible control valve secured to said cylinder, said valve comprising a pair of opposed cups of different diameter, a flexible connection between said cups, and means providing a connection for supplying fluid pressure to one end of said cylinder, said means being controlled by the smaller of said cups, said larger cup being exposed to the fluid pressure in said engine whereby said control valve operates under the influence of fluid pressure in said cylinder so that when the Huid pressure therein falls below a predetermined point the control valve operates to admit fluid pressure through said means providing a connection for supplying fluid pressure. p

9. A yielding pressure control valve for attachment to one end of the cylinder of a door operating engine comprising a pair of cup members of different diameters, a yielding member uniting said cup members, the larger of said cup members being exposed to the fluid pressure inthe exhausting end of the cylinder of said engine, and means connected to the valve for effecting the application of fluid pressure to the exhausting end of the cylinder of' the engine and controlled by the smaller of said cup members, whereby fluid pressure is admitted to the exhausting end of the cylinder of the engine when the pressure therein falls below a predetermined point.

l0. A yielding pressure control valve of the type described comprising a casing having a fluid pressure port and passage at one end and being substantially open at the other end,.a pair of cup members of different di ameters within said casing, and a yielding member uniting said cup members, the cup of smaller diameter being arranged to control said port and passage.

ll. A pressure control valve for applica tion to the end of the cylinder of a pneumatic engine comprising a casing havinga fluid pressure admission port at one end, and opposed cup members flexibly united within said casing, one of said cup members being adapted to control said port and the other of said cup members being adapted to be exposed to the fluid pressure within the end of the door engine cylinder so as to operate the smaller cup member to close said port when the pressure in the exhausting end of the cylinder is above a predetermined value.

In `testimony whereof I have hereunto set my hand on this 30th day of December, A. D.

PARIS R. FORMAN. 

